I'm having trouble desoldering a USB charge port connector?

Hi everyone, I'm trying to replace a charge port on my one touch tablet and I'm having a little bit of trouble. I'm new to soldering, never done it before, and I've been trying to desolder this connector for a while but it wont melt.

I heated up my soldering iron to over 400 C because I was getting frustrated and it still didn't do a thing. I know the heats fine because it melts my solder (the one in the bottle) instantly when I touch it.

Anyone have any tips on what I can do? This is how the port looks like:

Also, this might be a stupid question but, are those solder joints holding the connector in? lol, just want to make sure.